DESCRIPTION: There is a critical gap in our understanding of how public health insurance coverage affects the financial well- being of households. Because financial protection is a fundamental purpose of health insurance coverage, the costs and benefits of major public health insurance programs such as Medicaid cannot be assessed without credible, generalizable evidence on the impact of public health insurance coverage on household financial well-being. Despite its importance, there are no studies conducted at a national level on this topic. The long- term goal of this project is to better understand the effect of public heath insurance coverage on household financial well-being. The objective in this particular application is to assess the effect of the expansion of the Medicaid program resulting from the Affordable Care Act (ACA) on household debt, credit score, delinquency, bankruptcy and other measures of financial stability. The recent Supreme Court decision allowed states to choose whether or not to expand their Medicaid program as the ACA intended, and to date, twenty-two states have announced that they will not participate in the Medicaid expansion. This variation in expansion choices by states provides an opportunity to evaluate the effect of Medicaid coverage on the financial outcomes of low- income adults. The central hypothesis is that gaining Medicaid coverage will improve financial outcomes among low-income adults, and that these improvements will vary across demographic groups and across the pre-expansion characteristics of the state. Guided by strong preliminary results from a previous public health insurance expansion, this hypothesis will be tested by pursuing three specific aims: 1) Obtain national estimates of the effect of the Medicaid expansions of the ACA on a broad set of measures of financial well- being including credit score, delinquency behavior, debt, third-party collections, and bankruptcy; 2) Evaluate the differential effect of Medicaid coverage on financial well-being across individuals with different demographic characteristics and 3) Evaluate the differential effect of Medicaid coverage on financial well-being across localities that differ by te generosity of the state Medicaid program and the availability of safety net services. To accomplish these aims, we will use an innovative, powerful, new data set of over 38 million individual credit reports observed each quarter containing detailed financial data. This research will provide timely, relevant public health knowledge that will help policymakers at all levels accurately assess the costs and benefits of public health insurance expansions.